This invention relates to an apparatus for use with an automotive vehicle having an internal combustion engine and an automatic transmission to limit the engine speed below a predetermined value when the automatic transmission is in a specified position.
For example, Japanese Patent Kokai No. 60-4433 discloses a conventional engine speed limiting apparatus arranged to avoid a sudden vehicle starting by preventing transmission of a drive from the engine to the automatic transmission until the automatic transmission is changed from the "park" position to the "drive position" when the vehicle is at rest with the accelerator pedal being depressed. However, such a conventional apparatus permits the engine speed to increase to a great extent causing engine racing noises when the automatic transmission is in the "neutral position".
Another conventional engine speed limiting apparatus is disclosed in Japanese Patent Kokai No. 60-135632. The conventional apparatus is arranged to avoid a sudden vehicle starting by rapid throttle valve closure in response to a change to the "drive" position when the engine idling speed is high. With such a conventional apparatus, however, a long time is required to decrease the engine speed so as to provide an undesirable feed of starting lag to the operator when the automatic transmission is changed from the "neutral" position to the "drive" position while the engine speed is increasing.